| // Copyright 2009 The Go Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style |
| // license that can be found in the LICENSE file. |
| |
| //go:build aix || darwin || dragonfly || freebsd || (js && wasm) || linux || netbsd || openbsd || solaris || windows |
| |
| package poll |
| |
| import ( |
| "io" |
| "syscall" |
| ) |
| |
| // eofError returns io.EOF when fd is available for reading end of |
| // file. |
| func (fd *FD) eofError(n int, err error) error { |
| if n == 0 && err == nil && fd.ZeroReadIsEOF { |
| return io.EOF |
| } |
| return err |
| } |
| |
| // Shutdown wraps syscall.Shutdown. |
| func (fd *FD) Shutdown(how int) error { |
| if err := fd.incref(); err != nil { |
| return err |
| } |
| defer fd.decref() |
| return syscall.Shutdown(fd.Sysfd, how) |
| } |
| |
| // Fchown wraps syscall.Fchown. |
| func (fd *FD) Fchown(uid, gid int) error { |
| if err := fd.incref(); err != nil { |
| return err |
| } |
| defer fd.decref() |
| return ignoringEINTR(func() error { |
| return syscall.Fchown(fd.Sysfd, uid, gid) |
| }) |
| } |
| |
| // Ftruncate wraps syscall.Ftruncate. |
| func (fd *FD) Ftruncate(size int64) error { |
| if err := fd.incref(); err != nil { |
| return err |
| } |
| defer fd.decref() |
| return ignoringEINTR(func() error { |
| return syscall.Ftruncate(fd.Sysfd, size) |
| }) |
| } |
| |
| // RawControl invokes the user-defined function f for a non-IO |
| // operation. |
| func (fd *FD) RawControl(f func(uintptr)) error { |
| if err := fd.incref(); err != nil { |
| return err |
| } |
| defer fd.decref() |
| f(uintptr(fd.Sysfd)) |
| return nil |
| } |
| |
| // ignoringEINTR makes a function call and repeats it if it returns |
| // an EINTR error. This appears to be required even though we install all |
| // signal handlers with SA_RESTART: see #22838, #38033, #38836, #40846. |
| // Also #20400 and #36644 are issues in which a signal handler is |
| // installed without setting SA_RESTART. None of these are the common case, |
| // but there are enough of them that it seems that we can't avoid |
| // an EINTR loop. |
| func ignoringEINTR(fn func() error) error { |
| for { |
| err := fn() |
| if err != syscall.EINTR { |
| return err |
| } |
| } |
| } |